Electrical first-out indicator system for use with pneumatic controls on a petroleum process

ABSTRACT

An electrical indicator system is connected to a petroleum process where pneumatic controls are employed and where automatic shutdown will take place if any one of a plurality of parameters exceeds predetermined limits. The electrical system uses relays that are actuated by the pneumatic controls which indicate when a parameter goes outside limits. Each such relay has interlocking contacts with the circuits for all the other relays, so that the first actuated relay will lock out the remaining relays. This provides an indication of which condition was first outside limits.

U Umted States Patent [72] Inventors Allen M. Robin 5 Refe n e CitedAnaheim; UNITED STATES PATENTS gm?" Jess" bah 2,600,132 6/1952 Seaton340/2132 [2H APPL No. L762 2,701,872 2/1955 Marmorstone... 340/415 X[22] Filed Sept 29 1969 3,117,303 1/1964 Byme 340/415 X [45! Paemed Aug10 1971 3,144,046 8/1964 Seesse1berg.. 137/552 X [73] Assign Tam Inc.3,461,444 8/1969 Eisele 340/332 New York, N.Y. Primary Examiner-Henry T.Klinksiek Attorneysl E. Kavanagh and Thomas H. Whaley [54] ABSTRACT: Anelectrical indicator system is connected to a PETROLEUM PROCESSpetroleum process where pneumatic controls are employed and whereautomatic shutdown will take place if any one of a 6 Chums 3 Drawmg Figsplurality of parameters exceeds predetermined limits. The [52] U.S.Cl137/552, electrical system uses relays that are actuated by the pneu-137/554, 340/415 matic controls which indicate when a parameter goesoutside [51] Int. Cl ..Fl6k 37/00, limits. Each such relay hasinterlocking contacts with the cirl-l04q 3/02 cuits for all the otherrelays, so that the first actuated relay will [50] Field of Search137/552 lock out the remaining relays. This provides an indication ofwhich condition was first outside limits.

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionconcerns a petroleum process that has pneumatic controls andparticularly relates to an electrical system connected to act with thepneumatic controls ofthe petroleum process for providing first-outindication when the petroleum process is shut down by reason of some oneof the various parameters exceeding predetermined limits.

2. Description of the Prior Art In petroleum processes in general and inparticular with respect to a synthesis gas generating process, it isquite common to have the process controlled pneumatically. Also, it iswell known to provide an arrangement such that automatic shutdown of thesystem will take place if any of a given number of parameters in theprocess should exceed predetermined limits. This is to preventcatastrophic failure and possible loss of valuable equipment.

However, when such a shutdown occurs it may be very difficult and timeconsuming to determine the cause. One reason for this is that asshutdown takes place, all of the parameters will exceed limits.Therefore, it would be a great help and time saver to be able to have anindication of which was the first of the parameters to exceed itslimits, after an automatic shutdown has taken place.

Pneumatic control instruments have been designed in such a way to give afirst-out" indication when shutdown occurs. However, such instrumentsinvolve the use of more expensive and complicated pneumatic equipment,which alsorequires higher pneumatic pressures than are normally employedin the control systems to which this invention applies. Furthermore,some pneumatic firstout" systems have been constructed in such a waythat a malfunction of one of the pneumatic relays could activate theautomatic shutdown system even though the process is operating nonnally.

SUMMARY OF THE INVENTION Briefly, the invention relates to asynthesis-gas-generating process or the like, wherein a plurality ofparameters are monitored and the process includes means for shuttingdown said process if any of said parameters exceeds predeterminedlimits. Related to the foregoing, there is an electrical system forindicating the first of said parameters to exceed said limits. Thesystem comprises means for connecting a source of power to said system,and a first switch responsive to each of said parameters and actuatedwhen the parameter exceeds said limit. The system also comprises a relaycorresponding to each of said parameters and each relay having gplurality of simultaneously actuated contacts thereon providing secondseparate switches, one corresponding to each of said other parameters.The system also comprises circuit means for connecting one of saidsecond switches between said source of power and each of said otherrelays.

Again briefly, the invention relates to the combination with a refineryprocess or the like having pneumatic control and monitoring instruments.The process includes at least some pneumatically controlled valves forshutting down the process. It also includes a plurality of conditionmonitors which provide pneumatic signals indicative of said conditions,and a plurality of pneumatic control instruments actuated by saidpneumatic signals. It also includes pneumatic means for automaticallyactuating said valves when any one of said conditions exceedspredetermined limits. In combination with the foregoing refinery processthere is an electrical system for indicating which of said conditions isthe first to exceed said limits, and such electrical system comprisesmeans for connecting a source of electric power to said system. It alsocomprises a first switch actuated by each of said pnuematic controlinstruments, and a relay corresponding to each of said conditionmonitors and said relay having a plurality of contacts providing secondseparate switches one corresponding to each condition except for thatcorresponding to the said relay. It also comprises circuit means forconnecting one of said second switches between said source of electricpower and each of the other of said relays.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects andbenefits of the invention will be more fully set forth below inconnection with the best mode contemplated by the inventor of carryingout the invention, and in connection with which there are illustrationsprovided in the drawings, wherein:

FIG. I is a circuit diagram illustrating a simplified form of electricalsystem according to the invention;

FIG. 2 is an across-the-line type electrical circuit diagram whichillustrates a somewhat more complicated system as it is applied to asynthesis gas generation process; and

FIG. 3 is a schematic flow diagram illustrating asynthesisgas-generation process including an indication of some of theconnection points for an electrical first-out indicator system of thetype shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic concept of theinvention, as it pertains to an electrical system for providingfirst-out indication which relates to a petroleum process, isillustrated in FIG. 1. The process may have a plurality of parametersthat are being measured and/or monitored. And, the electrical first-outindicator system has a corresponding relay for each of these parameters,

In FIG.] there are shown four relays that are marked R-I, R-Z, R-3, andR-4. The four relays each have a coil I I, I2, I3 and 14 respectively.Each coil actuates a group of four-double throw switches, as indicated.There is respectively a mechanical connection for each which isschematically indicated by a dashed line l7, 18, I9 and 20 respectively.

In order to have each of the four parameters cause actuation of one ofthe relays under predetermined conditions, there is a correspondingpressure actuated switch 26, 27, 28 and 29, one for each of the fourrelays R-l, R-2, R-3 and R-4, respectively. The pneumatic system of thepetroleum process is arranged so that the parameters will actuate thepressure switches 26-29 when the parameters exceed the predeterminedlimits. Actuation of any one of the pressure switches will close thecontacts of that switch and consequently complete a circuit to energizethe corresponding one of the relay coils Il-l4. As soon as that happens,the contacts of that relay will be switched to the other position fromthat illustrated and consequently the circuit to all of the remainingthree relay coils will be broken. This will thus prevent energization ofthose relays and consequently whichever relay is energized gives anindication that the corresponding parameter was the first to exceed itslimits.

It will be appreciated and explained more fully below that the additionof some other circuits may be provided without changing the basicconcept of the invention. Also, it may be noted here that the first-outindication is provided by an indicator light 32 corresponding to relayR-1 and similarly lights 33, 34 and 35 corresponding to relays R2, R-3,and R-4 respectively. These lights will be energized or illuminated whenthe corresponding relay is actuated. Of course only the first to beenergized or illuminated will be that corresponding to the first-outindication, since the other contacts of that relay will remove the otherrelays from possible energization.

The basic system includes a switch 38 for energizing the whole system.There are a pair of terminals 39 for connecting a source of electricalenergy to the system.

To illustrate the operation of FIG. I it may be assumed that the systemswitch 38 is closed. Then assuming that the first parameter to gooutside limits is the one that actuates the pressure switch. 26 it willbe closed and it will energize coil II of relay R-I.

Such energizing circuit may be traced from the other side of switch 38,i.e., away from the terminal 39, over a circuit connection 42. Thecircuit continues from there over a conductor 43, and another conductor44 to a junction point 45. It then continues to one side, or contact, ofthe pressure switch 26. From the other side of switch 26, it continuesover a connection 48 to one side of a switch 49 of the group actuated byrelay R4. Then it goes via a connection 50 and a switch 52 to anotherconnection 51. The circuit continues over a switch 53 to a circuitconnection 56 that goes to one end of the relay coil 11. The other endof the coil 11 is connected via a circuit connection 57 to anothercircuit connection 58 that leads to a junction point 59. From junction Qthere is a circuit connection 60 leading to the other input terminal 39for the electrical energization of the system.

When the relay Rl is energized, its contacts will be switched over fromthe position illustrated to the other position for all of the fourswitch blades shown. Consequently, a switch 61 is opened and likewise aswitch 62 as well as a third switch 64. Each of these switches isconnected in the energizing circuit for one of the other relays R4, R2and R3 respectively so that none of them can be energized after therelay R-] has been energized.

There is an indicator-light circuit to energize one of the indicatorlights which correspond to the relays. This needs no explanation, itbeing sufficient to note by way of example that when the relay Rl isenergized a switch 63 is closed and completes a circuit for energizatinglight 32.

FIGS. 2 and 3 system Some of the benefits of a first-out indicatorsystem have been mentioned above. A particular embodiment will now bedescribed which illustrates an application of such a system to apetroleum process. In this case the process is a synthesis gas generatorunit which is schematically illustrated in FIG. 3. There are fouroperating parameters that can initiate a shutdown of the operation.These are indicated by the captions at the upper-left-hand position ofFIG. 3. They are labeled Quench Level, Oxygen," Process Water or CarrierGas" and Oil." However, the electrical system shown in FIG. 2 providesfor a total of seven parameter-controlled shutdown points, but theprinciples of the operation do not change.

In addition to the foregoing first-out shutdown indication points, thereis a manual shutdown indicator. Also there is a timer for determiningthe exact time when a shutdown occurs.

The automatic shutdown circuit is armed from the pressure in thegenerator of the foregoing process. However, the details of such ashutdown system with this equipment and circuits, is not necessary foran understanding of this invention. Such a shutdown system is importantto prevent catastrophic failures and possible loss of valuableequipment. In the past when a shutdown has occurred there has beendifficulty and often much time lost in making a determination as to theexact cause of the shutdown. Therefore, when a first-out electricalindicator system according to this invention is employed, any such timeloss is avoided. Furthermore, as already indicated, a timing indicatormay be provided so that the exact time when the first-out malfunctiontook place, may also be noted.

It will be observed that the FIG. 2 circuit diagram employs a differentconvention from that of the circuit diagram of FIG. 1. Thus, in FIG. 2there are parallel circuits shown from one side of a source ofelectrical supply to the other which would be connected to a pair ofterminals 65. The showings for switch contacts are not like those ofFIG. I, but are such that the symbol of two parallel lines crossed by asloping line, indicates switch (or relay) contacts that are closed whenthe relay is deenergized. On the other hand, the symbol of two parallellines without any crossed sloping line, indicated switch (or relay)contacts that are closed when the relay (to which these contacts belong)is energized. Which contacts belong to which relays is made clear by thecaptions with capital letter designations.

The relays are designated in the diagram as R" followed by a number.This designation is placed adjacent to both the contact symbols and thecircular symbols that represent the coil, or coils, contacts each relay.Furthermore, because of the number of relay contacts employed with eachof the seven relays that correspond to parameters of the petroleumprocess, there are twin relays used at each of these correspondingparameter-relay stations. Consequently, such relay coils are designatedby the captions including the letters A and B. However, no letterdesignations are employed with the contacts.

It will be appreciated that each of the foregoing seven relays, andcorresponding circuits, are substantially the same. Therefore, the FIG.2 diagram does not show all seven, but merely the first two and theseventh of the whole group.

The operation of the FIG. 2 system will be clear from an understandingof the description of the FIG. I circuit, in general. However, withspecific reference to FIG. 2, it may be noted that there is a pressureswitch 66 which is designated by the caption PS-l. This is under controlof the parameter that happens to correspond with this relay. The switch66 will be closed if that parameter goes outside of its predeterminedlimits. Closing of switch 66 will complete a circuit that will energizeboth relay coils 67 and 68. These have the captions R-IA and R-IBrespectively. The circuit is completed through relay contacts R2, R3,R4, R5, R6, and R7 which all stand as indicated in the diagram by asingle reference number 69. At the same time, an indicator light 72(designated Ll) will be energized.

It will be observed that the FIG. 2 system adds electrical holdingcircuits. This acts to keep the first relay pair and its indicator lightenergized until the whole system has been reset following he shutdownconditions. Thus, in the Rl relay circuit described above there is apair of contacts 70 that are captioned with the designation RI. Thesecontacts 70 will close when the relay Rl (coils 67 and 68) is actuated.The closing of these contacts completes a holding circuit across thepres sure switch 66 and the other relay contacts R2, R3, R4, RS, R-6 andR7 so that irrespective of whether any individual conditions shouldreturn within limits, the first-out indicator will hold its originalindication.

It will be appreciated, of course, that there is a normally closed setof contacts 71 in each of the other relay circuits, e.g., R2R7. Theseare all opened when the relay R1 is actu ated. They act to cut off thepossible later actuation of any of the other relays.

As another example, assume that another parameter, i.e., that whichactuates a pressure switch 74 (designated PS-Z) is the first to exceedlimits. Switch 74 will be closed and the circuit for relay R2 will becompleted from one side of the power source through all of the contactsthat stand closed, i.e., contacts 75 (designated Rl, R3, R-4, R5, R6 andR7). This will energize relay coils for the second relay, i.e., a coil76 and a coil 77. Also, the indicator light 78 (designated L-2) will beenergized. Energization of the relay R-2 will actuate the contactsdesignated R2. This includes contacts 80 that are located in each of theother groups of normally closed contacts. In addition, contacts 81 thatare normally open (when relay is deenergized) will be actuated to closethe holding circuit.

There is a timer circuit which includes a pressure switch 84 (designatedPS-8) that is closed when the system has developed sufficient pressureto activate the above-mentioned automatic shutdown. The switch 84 is inseries with a timer 85 that will be energized and will run followingstartup of the process, until a shutdown occurs.

There is provided a manual shutdown indicator that is in addition to thefirst-out shutdown indicator system described above. There are twoadditional relays (RIO) and 94 (RI I one additional pressure switch 93(PS-9) and also an indicator light 95 (L9) plus a pushbutton switch 96(SW9).

The operation of the manual shutdown may be described as follows withreference to FIG. 2. With the Generator" (FIG. 3) operating, all of theparameter controlled pressure switches (PS-I through RS7) and switch 93(PS-9) are open. while switch 84 (PS-8) is closed. The timer 85 isoperating, while a time-delay relay 91 (R8) is energized and a relay 92(R-9) is deenergized. All the contacts except for contacts 97 (R8), arein the position indicated by the symbols employed.

Asuming a manual shutdown is initiated, the pressure switch 93 (PS-9)will close. This energizes the relay 94 (R-II) and the indicator light95. Once energized they are locked on through contacts 99 (R-l I) andcontacts 100 (R-9). At the same time contacts 101 (R41) are opened whichrenders it impossible to energize any of the parameter relays R-Ithrough R-7 regardless of the position of the corresponding pressureswitches PS-I-PS7. Also, contacts 89 (R-Il) in the timer circuit areopened and the timer is stopped.

Now when the "Generator (FIG. 3) is brought on stream again, the manualshutdown switch 93 (PS-9) will be open. Consequently, the relay 94 (R-IIwill be deenergized when the relay 92 (R-9) is momentarily energizedduring startup, since the contacts 100(R-9) will be opened.

If we assume a shutdown was caused by one of the parameter-controlledpressure switches PS1PS7, it will energize its relay-and-alarm light. Itwill also stop the timer 85 and deenergize the relay 90 (R-l0) in thetimer circuit because of the opening of the corresponding one of thecontacts in a group of contacts 88. Therefore, contacts 98 (R-) will beopened and will prevent the relay 94 (R-I l) and the indicator light 95from being energized regardless of the position of the manual shutdownswitch 93 (PS-9).

It will be observed that there are momentary contact-type pushbuttonswitches captioned Test." Also, there is a toggle switch 104 thatcontrols power to the electrical system. By manipulating these in anexpected manner the alarm lights and relays may alarm checked. However,it is to be noted that because one alann circuit will always be lockedin alarm status if the Generator" (FIG. 3) is off line and power isapplied to the electrical system, there is provided an arrangement toautomatically clear such circuit. The arrangement involves the relay 92(R9) and the time-delay relay 9! (R8).

The sequence of events in the operation of the foregoing arrangement isas (R- 8) With power an and the Generator" (FIG. 3) 011' stream, therelays 91 (R-8) and 92 (R-9) are deenergized and contacts 105 (R-9) areclosed. This permits current to flow to the alarm circuits (parametercontrolled). As the Generator (FIG. 3) is brought on stream, the switch84 (PS-8) is closed and this energizes the time-delay relay 91 (11-8)which closes the contacts 97 (ll-8) for the duration of the time-delayperiod. This energizes the relay 92 (R-9) for that length of time andopens the contacts 105 which deenergizes all of the alarm relaycircuits. After the time delay period, the contacts 97 (R-8) are openedwhich deenergizes the relay 92 (R-9) and closes the contacts 105restoring power to the alarm circuits. Since the Generator" (FIG. 3) isthen on stream none of the indicator (alarm) lights will be lit.

FIG 3 is clearly self-explanatory and it is pointed out that the varioussymbols employed are explained by appropriate legends. The processillustrated is a synthesis gas generator and four of the parameters areindicated by the captions Quench Level, Oxygen," Process Water orCarrier Gas" and Oil." Each of these conditions in the system ismonitored by the pneumatic system in the manner indicated. This includespressure controllers 107, I08, 109 and 110. These are pneumaticinstruments that are snap acting and allow either 0 or maximuminstrument air pressure to be applied to the output. In each casethe-output is connected to the diaphragm of a corresponding valve asillustrated. It will be observed also that the inputs to the controllersare taken from an appropriate monitoring instrument in each case, e.g.,the oxygen flow is monitored by a flow transmitter 117 connected to anorifice 118, as indicated.

As shown by the square symbols marked FO," there is apneumatic-connection point in the system of FIG. 3 where each pressureswitch (e.g., switch 74 of FIG. 2) is connected. For example, aconnection point 111, I12, I13 and 114 is indicated to? each of the fourcaptioned parameters, respective? It will be appreciated that a systemaccording to this invention may be employed with other and differentprocess having automatic shutdown which might have more or lessparameters to be monitored.

While the foregoing embodiments of the invention have been described inconsiderable detail in accordance with the applicable statutes, this isnot to be taken as in any way limiting the invention, but merely asbeing descriptive thereof.

1 claim:

1. In a synthesis-gas-generating process, or the like, wherein aplurality of parameters are monitored and including means for shuttingdown said process if any of said parameters exceeds predeterminedlimits,

an electrical system for indicating the first of said parameters toexceed said limits, comprising means for connecting a source of power tosaid system,

a first switch responsive to each of said parameters and actuated whenthe parameter exceeds said limit,

a relay corresponding to each of said parameters and each relay having aplurality of simultaneously actuated contacts thereon providingsecond-separate switches, one corresponding to each of said otherparameters, and

circuit means for connecting one of said second switches between saidsource of power and each of said other relays.

2. The invention according to claim 1 wherein said first switches areclosed when actuated, and

wherein said second-separate switches are opened when the relaysassociated therewith is actuated whereby one of the other relays can beactivated thereafter.

3. The invention according to claim 2 further including a third switchon each of said relays, and

second circuit means for connecting said third switch in a holdingcircuit for retaining actuation of the actuated relay even after thesaid parameter has returned within said limits.

4. In combination with a refinery process or the like having pneumaticcontrol and monitoring instruments, and including at least somepneumatically controlled valves for shutting down the process,

said process also including a plurality of condition monitors whichprovide pneumatic signals indicative of said conditions,

a plurality of pneumatic control instruments actuated by said pneumaticsignals, and

pneumatic means for automatically actuating said valve when any one ofsaid conditions exceeds predetermined limits,

the combination of an electrical system for indicating which of saidconditions is the first to exceed said limit, comprising means forconnecting a source of electric power pneumaticcontrol said system,

a first switch actuated by each of said pneumatic-control instruments,

a relay corresponding to each of said condition monitors and said relayhaving a plurality of contacts providing second-separate switches, onecorresponding to each condition except for that corresponding to thesaid relay, and

circuit means for connecting one of said second switches between saidsource of electric power and each of the other of said relays.

5. The invention according to claim 4 wherein said first switches areclosed when said control instruments are actuated, and

wherein said second switches are opened when the relay associatedtherewith is actuated whereby none of the other relays can be actuatedthereafter.

6. The invention according to claim 5 furtherincluding a third switch oneach of said relays, and

a second circuit means for connecting said third switch in a holdingcircuit for retaining actuation of the actuated relay even after thesaid condition has returned within said limits.

* g;;g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,598,146 Dated August 10, 1971 Inventor(g) ALLEN M. ROBIN and DALE R.JESSE It is certified that error appears in the above-identified patentand that: said Letters Patent are hereby corrected as shown below:

Column 3, line 48, "with this equipment" should read with its equipmentColumn 4, line 74, "RS-7" should read Ps-7 Claim 1, line 12,"second-separate" should not be hyphenated Claim 2, line 3,"second-separate" should not be hyphenated Claim 2, line 4, "whereby oneof" should read whereby none of Claim 4, line 10, "said valve" shouldread said valves Claim 4, lines 16 'power pneumatic-control said" shouldand 17 read power to said Claim 4, line 22, "second-separate" should notbe hyphenated Sig-nod and sealed this 18th day of April 1972.

ISEAL) ittest:

GD'z-IARD I LI LETCIILEELJR. ROBERT GOT'ISCHALK [testing OfficerCommissioner of Patents

1. In a synthesis-gas-generating process, or the like, wherein a plurality of parameters are monitored and including means for shutting down said process if any of said parameters exceeds predetermined limits, an electrical system for indicating the first of said parameters to exceed said limits, comprising means for connecting a source of power to said system, a first switch responsive to each of said parameters and actuated when the parameter exceeds said limit, a relay corresponding to each of said parameters and each relay having a plurality of simultaneously actuated contacts thereon providing second-separate switches, one corresponding to each of said other parameters, and circuit means for connecting one of said second switches between said source of power and each of said other relays.
 2. The iNvention according to claim 1 wherein said first switches are closed when actuated, and wherein said second-separate switches are opened when the relays associated therewith is actuated whereby one of the other relays can be activated thereafter.
 3. The invention according to claim 2 further including a third switch on each of said relays, and second circuit means for connecting said third switch in a holding circuit for retaining actuation of the actuated relay even after the said parameter has returned within said limits.
 4. In combination with a refinery process or the like having pneumatic control and monitoring instruments, and including at least some pneumatically controlled valves for shutting down the process, said process also including a plurality of condition monitors which provide pneumatic signals indicative of said conditions, a plurality of pneumatic control instruments actuated by said pneumatic signals, and pneumatic means for automatically actuating said valve when any one of said conditions exceeds predetermined limits, the combination of an electrical system for indicating which of said conditions is the first to exceed said limit, comprising means for connecting a source of electric power to said system, a first switch actuated by each of said pneumatic-control instruments, a relay corresponding to each of said condition monitors and said relay having a plurality of contacts providing second-separate switches, one corresponding to each condition except for that corresponding to the said relay, and circuit means for connecting one of said second switches between said source of electric power and each of the other of said relays.
 5. The invention according to claim 4 wherein said first switches are closed when said control instruments are actuated, and wherein said second switches are opened when the relay associated therewith is actuated whereby none of the other relays can be actuated thereafter.
 6. The invention according to claim 5 further including a third switch on each of said relays, and a second circuit means for connecting said third switch in a holding circuit for retaining actuation of the actuated relay even after the said condition has returned within said limits. 